Electronic code permutation locking apparatus

ABSTRACT

This invention relates to electronic combination locks for operating an electromechanical apparatus, such as a door latch or ignition lock, when in its operative condition. It comprises a plurality of selectable operators digit switches which when operated in a predetermined sequence will switch the lock to its operative condition. A number of bistable or on-off devices are provided with each connected to a predetermined one of the selectable operators switches for operation to a first condition upon operation of its associated operators switch in the sequence and to the other condition upon subsequent operation. A multiple switch and/or logic component is connected to the plurality of bistable devices for sensing a predetermined pattern of conditions from the bistable devices indicative of the last digit of the sequence. A further device is responsive to the sensing means, when sensing the predetermined pattern, to render the lock operative for operating the electromechanical device. Switching means is provided for supplying power to operate the lock, and it is a two position device for supplying power in one of its conditions of operation only, which condition is established by proper selection of one of the operators switches. Reset means are provided for interconnecting the on-off or bistable devices and switching means to interrupt the power when anyone of the operators switches is operated out of the sequence, and a timing circuit is provided similarly to cut off the power to the bistable devices through the switching means after a predetermined interval of time. If the lock has been actuated, power is established over a separate line to the load and once operated is thus not further affected by the switching means or timing circuit until released.

United States Patent [72] Inventor James G. Wolfe 404 Branch Drive,Silver Spring, Md. 20901 [21] Appl. No. 719,022 [22] Filed Apr. 5,1968[45] Patented Apr. 2 1971' [54] ELECTRONIC CODE PERMUTATION LOCKINGAPPARATUS 16 Claims, 2 Drawing Figs.

52 us. C1. 340/147,

340/164, 340/167, 340/168 [51] Int. Cl H04q 3/02 [50] Field of Search340/164,

[56] References Cited UNITED STATES PATENTS 3,080,547 3/1963 Cooper340/164 3,175,191 3/1965 Cohn et a1. 340/164 3,380,024 4/1968 Watkinson340/164 3,441,808 4/1969 Crane 340/164X Primary Examiner-Harold I. PittsAttorney-Wilfred G. Caldwell lIOv ABSTRACT: This invention relates toelectronic combination locks for operating an electromechanicalapparatus, such as a door latch or ignition lock, when in its operativecondition. It comprises a plurality of selectable operators digitswitches which when operated in a predetermined sequence will switch thelock to its operative condition. A number of bistable or onoff devicesare provided with each connected to a predetermined one of theselectable operators switches for operation to a first condition uponoperation of its associated operators switch in the sequence and to theother condition upon subsequent operation. A multiple switch and/orlogic component is connected to the plurality of bistable devices forsensing a predetermined pattern of conditions from the bistable devicesindicative of the last digit of the sequence. A further device isresponsive to the sensing means, when sensing the predetermined pattern,to render the lock operative for operating the electromechanical device.Switching means is provided for supplying power to operate the lock, andit is a two position device for supplying power in one of its conditionsof operation only, which condition is established by proper selection ofone of the operators switches. Reset means are provided forinterconnecting the on-off or bistable devices and switching means tointerrupt the power when anyone of the operators switches is operatedout of the sequence, and a timing circuit is provided similarly to cutoff the power to the bistable devices through the switching means aftera predetermined interval of time. If the lock has been actuated, poweris established over a separate line to the load and once operated isthus not further affected by the switching means or timing circuit untilreleased.

PATENTED mam -3576.836

' SHEU 1 [IF 2 INVENTOR JAMES G.WOLF'E 2 ATTORNEY ELECTRONIC CODEPERMUTATION LOCKING APPARATUS The invention relates to electronicactuated locks wherein a predetermined permutation is set within thelock, and the latter can only be rendered operative by proper operatormanipulation of a plurality of switches in a predetennined sequence. Thelock is provided for maximum security and convenience in safeguardingbuildings or rooms or the like in the form of a door lock, or vehiclesor other devices in the form of an ignition or operating lock.

In its application to doors, lockers, storage areas, and the like, thelock preferably comprises a switching on-off device, e.g. monostablemultivibrator, for controlling power to the remainder of the lock. Aseries gate is rendered operative when the monostable multivibrator isactuated to one condition by selection of one of the operators switches,to admit power to a plurality of on-ofi or bistable devices. The latterdevices are preferably flip-flops connected to operate in apredetermined sequence, e.g. as a binary chain, upon closing or furtherof the operators switches in proper sequence. The outputs of each of theflip-flops may be brought to a multiple switching and sensing meanswhich is set to select a predetermined condition, i.e. binary numberdeveloped by proper actuation of the flip-flops to render the lockactuator mechanism operative, preferably by removing a short circuit inparallel with the load operating initiating device, to permit theactuating mechanism to be operated from the same source of power supplyfor the locking mechanism.

The monostable multivibrator. includes a timing circuit whichestablishes a predetermined time interval, such as 8 seconds, forproperly operating all necessary operators switches. The timing circuitautomatically resets the monostable multivibrator to its quiescentstate, at the end of the time interval, to cut off power to theflip-flops thereby making it mandatory that operation of the switch berapidly achieved.

Additionally, each of the operators switches includes a resettingconnection to the monostable multivibrator, such that operation of anyof the operators switches out of proper operation of the lock. It issettable to signal after one or a predetermined number of errors.

Further, an emergency power supply is maintained in charging connectionwith the. circuitry so that the lock may be operated even when thesupply voltage is out.

A simpler embodiment is disclosed, in the form of an ignition lock,operative from the power supply of the vehicle. In the interest ofeconomy, the multiple switching and sensing means is replaced by alogical element which can be satisfied from the flip-flops collectivelyin one condition to supply power to the starter motor. The emergencypower supply is ordinarily not necessary, but the alarm circuit may beincorporated if desired.

With the foregoing in mind, it is among the objects of the invention toprovide an electronic combination lock which is tamperproof and offersmaximum security. A further object of the invention is the provision ofan electronic combination lock in which the pennutation sequence, aswell as the number of operators switches necessary to operate the lockcan be readily set to a predetennined pennutation.

Another object of the invention is the incorporation of an alarm systemfor signalling improper operation of the look after a given number oferrors, as well as an emergency power supply automatically ready for usewhenever the main power supply fails.

Other and further objects of the invention will become apparent from thefollowing detailed description thereof, when taken in light of theaccompanying drawings, wherein:

FIG. 1 is an electrical circuit diagram of the preferred embodimentfacilitating change of the predetermined pennutation and providing thealarm and emergency power functions, and

FIG. 2 is a circuit diagram of a simplified electronic combination lock,shown in its application to a vehicle ignition lock.

In FIG. 1, transformer 20 is provided to step the supply voltage, e.g. l10 volt AC down to a useable voltage level for the solid statecomponents to be described. A full wave bridge rectifier comprisesdiodes 21, 22, 23 and 24 to provide a positive and negative unfilteredDC voltage with a common return lead 25 serving as a center tap oftransformer 20. Capacitors 27, 28 and 29, along with resistors 31, 32,and 33 filter the rectified AC voltage to provide a smooth DC voltageoutput for the logic circuitry.

Further, resistors 32 and 33 form a voltage divider with a level ofvoltage at their junction for determining the level of the multivibratortriggering pulses.

The switching means, which controls the application of power to thelock, is shown as the monostable multivibrator comprising transistors Q1and Q2. It is connected in the usual configuration, including resistors34, 35, 36 and 37, as well as capacitor 39. This monostablemultivibrator controls the base current to the positive voltage seriesgate transistor Q2a.

In the quiescent state, the monostable multivibrator Q1, Q2 back biasesthe base 40 of the positive voltage gate transistor Q2a throughsaturated transistor 02. Thus 02a is not conducting in the quiescentstate and the power to the remaining circuitry is off. The transistorsin FIG. 1 may all be of type 2N3567 and the circuitry is shown for thisNPN type wherein negative signals will turn off these transistors. Itwill, of course, be appreciated that with polarity reversal PNPtransistors could be substituted. A negative pulse applied to base 81 ofQ2 will change conduction to Q1 and close Q2a, as will be furtherexplained in connection with the operators switches.

Next, the three bistable multivibrators supplied with operating powerover gate 02a and used for developing a series of binary codes will bedescribed. The first bistable multivibrator includes transistors Q3 and04, with resistors 42, 43, 44 and 45. The second bistable multivibratorcomprises transistors Q5 and Q6, along with resistors 51, 52, 53 and 54.The third bistable multivibrator comprises transistors Q7 and 08, alongwith resistors 61, 62, 63 and 64.

ln the quiescent condition, with series gate Q2a open, the bistablemultivibrators Q3, Q4; Q5, Q6 and Q7, Q8 are nonoperative.

At the lower left of FIG. 1, there is shown operators pushbutton 71,corresponding to the first digit of the permutation l 3 2 4 6. When theoperator closes pushbutton 71, the negative voltage from the junction ofresistors 32 and 33 is applied over line 73, via patch cord 75 tocapacitor 77, negatively charging this 0.005-microfarad capacitor. Theresulting negative triggering pulse back biases transistor Q2 over lead79 to its base 81 causing the monostable multivibrator Q1, O2 to changestate with conduction being transferred to transistor Q1. Capacitor 39discharges through resistors 34 and 35 and transistor 02a is forwardbiased through resistors 36 and 38, enabling it to conduct current forthe length of time it takes capacitor 39 to discharge. It has been foundthat approximately 8 secondsenables a person familiar with thecombination to operate the lock and accordingly, the parameters may beset for an 8-second discharge of capacitor 39 or to another interval ifdesired. For example, if fewer pushbuttons are used in a permutation,with-perhaps fewer bistable multivibrators, such as only Q3, Q4; Q5, Q6,the time interval may be shortened. Conversely, if more than threebistable multivibrators are employed and if additional pushbuttons areused, it may be desirable to lengthen the time interval.

When the monostable multivibrator Q1, Q2 changed state, it generated anegative pulse from the collector 83 of Q1. This negative pulse chargedcapacitor 85 (connected to Q4); capacitor 86 (connected to Q6) andcapacitor 88 (connected to 08), by way of lead 89 and diode 90. Theeffect of the negative charging of'these capacitors is to back bias Q4,Q6 and Q8 of the multivibrators. Diode 90 prevents positive pulses,generated by multivibrator Q1, Q2 when it goes back to its quiescentstate, from forward biasing Q4, Q6 and Q8.

The output of each bistable multivibrator Q3, Q4; Q5, Q6 and Q7, O8 isconnected to switch 100 by leads 101, 102 and 103. Switch 100 is arotary switch provided to select the number of digits in thepermutation. It is shown set for a digit permutation, as will beexplained more fully hereinafter.

Switch 100 connects the preselected bistable multivibrator(s)(comprising the sensed pattern) to the base 105 of shunting transistorQ9, by way of one or more of the diodes 106, 107 and 108, over lead 109and 15,000-ohm resistor 110. Resistor 110 is designed to give theforward bias to saturate Q9 under extreme temperature conditions anddiodes 106, 107 and 108 isolate the multivibrators from each other.Transistor Q9 will remain forward biased until the last digit of thepermutation has been pushed. While O9 is forward biased, it shunts thebase current to load actuating base of transistor 010 to prevent Q10from conducting current which in turn prevents the load (electric dooropener coil 112) from being energized. It is noted that the power pathfor coil 112 is over lead 113 to the rectifier section of the outputside of transformer 20. Thus, only if the proper permutation is placedon the operators switches (such as 71), will the short be removed topermit operation of the coil 112, but then the power circuit is direct.

A 560-ohm resistor 114 controls Q9 collector current and Q10 basecurrent with lOO-ohm resistor 115 being a current limiting resistordesigned such that the collector saturated voltage of Q9 will not causeforward biasing of Q10. Diode 116, which may be of 1N536 type, shuntsthe high level spike produced by the collapsing field of the electronicdoor opener thereby protecting transistor Q10 from possible permanentdamage.

it will now be shown how the switch 100 enables the preselection of thenumber of digits required for the operative permutation. It hasheretofore been explained that in the quiescent state all transistors Q3through Q8 are off, but closure of switch 71 back biased transistors Q4,Q6 and O8 to turn on transistors Q3, Q5 and Q7. Since the output leads101, 102 and 103 from the bistable multivibrators are taken from the Q4,Q6 and Q8 sides, these voltage levels will be high once switch 71 isclosed. The high voltage is represented by digit 1 in the followingtable, and no voltage output by the digit 0. The table columns areprovided from left to right for multivibrators Q3, Q4; Q5, Q6 and Q7,Q8, with the digits being placed in by the operators switches, such as71.

LOGIC CODE (FIG. 1)

Permutation 1 3 2 4 6 From the above table, it may be seen that for thefirst digit, all bistable multivibrator leads 101, 102 and 103 carry theoutput voltage level. Lead 101 extends to an unconnected terminal 5 inthe upper segment of switch 100, and similarly lead 102 extends tounselected terminal 6 in the left-hand segment. However, lead 103extends to terminal 5 which is connected and selected; it extendsthrough diode 108 and lead 109 to base 105 of transistor Q9 maintainingthe transistor saturated. As the three bistable multivibrators areoperated in binary fashion, it will be noted that the second digitproduces no output on lead 101 from Q4, because this multivibrator hasnow been flipped with conduction on Q4. However, the remaining twomultivibrators are unchanged and Q9 remains saturated. The third digitchanges multivibrator Q3, Q4 and also Q5, Q6 but the voltage levelremains at lead 103. For the fourth digit,

lead 103 is still producing a voltage level, but for the fifth digit,the condition for conduction in Q7, is switched to conduction in Q8 andthis condition produces no output on lead 103. Since leads 101 and 102are not connected through switch 100, Q9 is turned off to causeconduction in Q10 to actuate load 112. Thus, it may be seen by rotatingswitch 100, the permutation code may be made up of any number of digitsherein illustrated, as 37 for three multivibrators, or 1--7 if switchsegments carried further contacts. For example, if a 7- digitpermutation were desired, switch 100 would be rotated so that thesegments all made connections with their number 7 terminals and from thechart, it can be seen that lead 101 would be at the high level and leads102 and 103 at the low level. By selecting both leads 102 and 103 atswitch 100, O9 is turned off and Q10 on for the first time in anypattern 1-7, so it may be seen that the diodes 106, 107 and 108 areconnected in logical AND or in OR relation permitting sensing of thepredetermined pattern for lock actuation, and the code pattern continuesas a decreasing binary count.

it will now be shown how the operators switches, such as 71, if operatedin the proper sequence, will step the multivibrators in accordance withthe logic code above depicted. First, it should be noted that thesemultivibrators are isolated as to input triggering pulses from thecollectors, preventing false triggering, by resistors (in circuit withQ3), 121 (in circuit with Q5), 122 (in circuit with O6) and 123 (incircuit with Q7). Each resistor has a value of 150,000 ohms. Theconnection of the bistable multivibrator collectors, through theseisolating resistors, such as lead for resistor 120 extending to thejunction of 0.005-microfarad capacitor 131 and diode 132, provides ameans of steering input pulses, these paths being duplicated for theother transistors. Returning now to the operators switches, it will benoted that switch 135, in the position of the third switch is connectedby patch cord 136 to serve as the second input. Upon closure of switch135, capacitor 137 immediately charges and the negative triggering pulsefollows lead 138 and lead 173 to the base of Q3 where it back biases O3in the first bistable state multivibrator, causing it to change state.Since capacitor 139 was already charged from the positive voltage at thecollector of Q6 over lead 140 and 141, diode 138 did not transfer thenegative triggering pulse and thus the alarm circuit (shown to the lowerright of FIG. 1) is not influenced or actuated over alarm lead 144 andmonostable Q1, Q2 is not reset to its quiescent state.

Next, the pushbutton 150, corresponding to the third digit in thepermutation 1 3 2 4 6, is now depressed. Patch cord 151 permitscapacitor 152 to charge and the negative pulse is steered through diodes154 and 155 to back bias transistors 04 and Q5 over leads 156, 157 forQ4 and 158 for Q5; thus, both the first and second bistable statemultivibrators change state, as is shown in the above logic code.

The fourth pushbutton is depressed to negatively charge capacitor 171,which in turn back biases transistor Q3 over leads 172 and 173 to causethe first multivibrator to change state.

The last (sixth) pushbutton 180, corresponding to the fifth digit in thepermutation, is now depressed and capacitor 181 charges and generates anegative pulse through diodes 182, 183 and 184, back biasing transistorQ4 over leads 185 and 157, O6 over lead 186 and Q7 over lead 187,thereby causing all three bistable multivibrators to change state, asshown in the code above for the fifth digit. At this time, there is nooutput from the first and second bistable multivibrators. Switch 100 isset for the 5-digit permutation and only the third bistablemultivibrator (07,08) is connected to the base 105 of shuntingtransistor Q9. With no output from this third multivibrator, Q9 turnsoff and load actuating transistor Q10 is forward biased throughresistors 114 and 115 causing Q10 to conduct and go into the saturatedstate. This action energizes coil 112 and the door is unlocked.

The switch 100 will accommodate up to seven digits as iridicated, inwhich event in position 7, additional operators switches 201 and 202could be employed in the manner hereinbefore described. The eighth,ninth and th switches 203, 204 and 205 are connected directly to thealarm line 144 and operation of any one of these latter three switchesinstantly removes the power (over lead 226) and sets off the alarm orregisters in the alarm mechanism. Of course, it will be apparent that byusing patch cords between the operator switches and the diode steeringmatrix that any one or more of the eighth, ninth or l0th positions couldbe incorporated into the permutation, in lieu of other prior switches.

The sequence of events from the depression of the first pushbutton 71 tothe depression of the final pushbutton 180 must take place within thepredetermined 8 seconds. After 8 seconds has elapsed, the logiccircuitry resets automatically to its quiescent state with O2 assumingconduction so that series gate 02a is opened. Furthermore, thepushbutton corresponding to the digits must be pushed in the propersequence and additionally no pushbutton not associated with thepermutation must be pushed or the circuitry will reset to its quiescentstate and the alarm circuit will be influenced or tripped.

Each pushbutton except the one (71) corresponding to the first of thepermutation is connected to the alarm circuit over lead 144 such that ifan improper pushbutton is pushed or a pushbutton pushed out of sequencethen the alarm circuit can be tripped and audible sound will occur untilmanually reset. By way of example, assume that pushbutton 170 is pushedout of sequence. This charges capacitor 220 which in turn generates anegative pulse through diode 221 along lead 144 and through 18,000-ohmresistor 222. At the junction of resistors 222, 223 and resistor 224,diode 227, the pulse divides and follows two paths. The first path isalong lead 226 to diode 227 to back bias transistor Q1 causing themonostable multivibrator to change state back to its quiescent statewhich resets the entire system.

The second path is through resistor 224 (a current limiting resistor)and diode 225 to back bias transistor Q11 for the time duration of thenegative pulse. This action causes the collector voltage of Q11 to gopositive which forward biases transistor Q12 over 1,000-ohm resistor230, which transistor is connected as an emitter-follower and thebiasing action persists for approximately 300 microseconds. During thetime interval that Q12 is forward biased, capacitor 231, which may be aS-microfarad capacitor, is charging through resistor 232, Q12 and diode233. The time to fully charge capacitor 231 is considerably longer thanthe time that Q12 is forward biased, such that each time the alarmcircuit receives a signal because of an error, capacitor 231 charges acertain percentage of full charge. Switch 235 selects the number oferrors required to trigger the alarm. It is adapted to add resistance asit is moved from position 1 to position 4 with resistor 236 being 3megohms, resistor 237 being 2.75 megohms and resistor 238' being 1.5megohms. This switch, in position 2 as shown, is set to give an alarmwhen three errors have been committed. The first error causes capacitor231 to charge a certain percentage of full charge and hold this charge.Diode 233 prevents capacitor 231 from rapidly discharging through20,000-ohm resistor 240. The second error boosts the charge on capacitor231 and the third error steps the charge to the necessary voltage levelrequired to forward bias the silicon-controlled switch 250, which may beof the 3N84 type.

When SCS 250 is gated on, the oscillator including unijunctiontransistor 251, l-microfarad condenser 252 and 1,000- ohm resistor 253and 330-ohm resistor 254 is energized to oscillate and produce anaudible tone that will persist until the reset switch 255 is pushed toopen the circuit. This alarm can, of course, be concealed or within thelocked room. Resistors 236, 237, 238 and 3-megohm resistor 260 arecurrent limiters for the cathode gate control of the SCS. The0.02-microfarad capacitor 261 is a transient signal filter. The100,000-ohm resistor 263 controls the rate effect" of the SCS. Speaker265 provides the audible alarm. When capacitor 252 charges throughresistor 253 to a level that forward biases unijunction 251, theunijunction conducts through the speaker causing the tone. Capacitor 252rapidly discharges through the emitter base one junction and the cyclerepeats itself.

The emergency power supply consists of batteries 270 and 271 in serieswith rectifiers 272 and 273 to permit trickle charging during normalcircuit operation and to provide a source of the proper polarity voltagefor emergency use.

In FIG. 2, there is shown a permutation ignition lock for vehicles andit comprises a simpler embodiment of the door lockdescribed, but ingeneral, the same operating principles otherwise obtain.

The power source, for the ignition source, is supplied by the vehiclebattery. However, the monostable multivibrator of the previous lock isnow replaced by a bistable multivibrator 300 comprising transistors 301and 303. The function of this device remains generally the same, namelyto control the supply of power to the logic circuit. The load nowcomprises relay coils 305 and 307 for operating, respectively relaycontacts 309 for the vehicle ignition coil circuitry and relay contacts311 for the starter motor circuitry. The first relay 309 also controlsthe gauges of the instrument panel, radio, lights, and otheraccessories, while the contacts 311 only control the starter motorcircuit.

Additionally, only two logic bistable multivibrators 320 and 321 areshown, including respectively transistors 322, 323 and 324, 325.

The first pushbutton 330 is pushed causing the switching bistablemultivibrator to change state. Accordingly, in the permutation 2 1 4 3,the pushbutton 330 extends negative potential from lead 331 over patchcord 33 to produce a negative pulse at capacitor 334 which passesthrough diode 335 to turn off transistor 303. In turn, series gatetransistor 340 is forward biased to continue power line 341 to the logicbistable multivibrators 320 and 321. The negative pulse from pushbutton330 does not reset multivibrator 300 because capacitor 332 is at apositive potential from the +3 to +6 volt source and no pulse is passedover lead 329 including diode 328 to reset line 390-390 After transistor301 is conducting, the remaining pushbuttons in the permutation arepushed and the operation is the same as previously described. Again, alogic code is presented, but it is a code which operates when bothmultivibrators 320 and 321 are producing no output voltage.

LOGIC CODE (FIG. 2) FOR IGNITION LOCK Permutation 2 1 4 3 In the abovecode, it will be noted that in the quiescent state, neithermultivibrator 320 or 321 is actuated. However,- when conduction isestablished in transistor 301, it causes a negative pulse in lead 340which passes over diode 341 to turn off transistor 323 over capacitor342 and also turn off transistor 325 over capacitor 343 thus affordingthe output conditions in the above chart for the first digit, namely 1and l.

The same principle obtains until the last digit is entered (fourthdigit) by closure of switch 350. This provides a negative pulse overpatch cord 351, via capacitor 352, diode 353 and leads 354 and 355,toturn off transistor 322, thus affording a zero output in the left-handsegment of the above chart. Transistor 324 of the second multivibratoris already off as a result of the third digit which applied a negativepulse via lead 360, thereby producing a zero output in the left-handcolumn.

From the above, it can be seen that this is the first time that nooutputs have been applied to both diodes 370 and 371 connected as an ANDor as an OR circuit and accordingly, the transistor 375 (correspondingto transistor Q9 of FIG. 1) is no longer forward biased, and power isnow available directly to the relays 305 and 307. These relays areprotected by diodes 306 and 308 during collapse of their magneticfields. However, starting motor relay does not energize until thestarter button 380 is depressed.

To shut the ignition system off, the pushbutton 330, relating to thefirst digit of the permutation, is depressed for the second time causingthe first bistable multivibrator 300 to switch conduction back to itsclosed condition, i.e. transistor.

303 becoming conductive, and cut off the power supply.

Similarly, the reset line 390-390 is provided as before to switch thestate of multivibrator 300 to cut ofi the power whenever a button isdepressed out of the sequence or when a button not associated with thepermutation is depressed thereby affording the safety protectionfunction.

It will now be appreciated that the variations shown in FIGS. 1 and 2may be used in any combination, as for example, the multiple switch 100of FIG. 1 could be incorporated in the circuitry of FIG. 2 to permit theselection of a different number of digits for the permutation to startthe motor of the vehicle. Switch 100 may be omitted from the circuit ofFIG. 1 in accordance with the teachings related to FIG. 2.

Additionally, the use of the first stage for supplying power can bederived from either a monostable or bistable stage. Also, of course, thealarm circuitry of FIG. 1 could be incorporated into FIG. 2.

For these reasons, it is intended that the invention beassociatedoperators switches in said sequence and to the other condition uponsubsequent operation; means interconnecting said bistable means foroperation in accordance with binary sequencing; output circuits for eachbistable means to provide outputs indicative of the condition ofoperation; multiple switching means connected to the output circuits ofthe plurality of bistable means for preselecting the number of operatorsswitches to be operated in the sequence to render said lock operative;sensing means connected to the multiple switching means and responsivethereto to sense a predetermined pattern of conditions in accordancewith binary code therefrom indicative of the last digit of saidsequence; means responsive to the sensing means when sensing saidpredetermined pattern to render the lock operative for operating theelectromechanical means; switching means for supplying power to operatethe lock, said switching means comprising two position operating meansfor supplying power in one of its conditions of operation; and resetmeans interconnecting the operators switches to the two position meansto interrupt the power when one of the operators switches is operatedout of said sequence.

2. The lock of claim 1 wherein the bistable means and the switchingmeans comprise multivibrators.

3. The lock of claim I wherein the switching means comprises amonostable multivibrator including timing means for resetting it, andthe reset means are connected to reset the multivibrator independentlyof the timing means.

4. The lock of claim 1 further comprising circuit connections from theswitching means to each bistable means to establish a predetennined setof operating conditions among the bistable means upon operation of theswitching means to its one condition of operation, and said switchingmeans being operated to said one condition of operation by actuation ofits associated operators switch.

5. The lock of claim 4 wherein said switching means comprises a powerlead connected from a source of power to the bistable means, a seriesgate connected in the lead to open and close it, said switching meansfurther comprising a multivibrator for closing the series gate when insaid one condition of operation.

6. The lock of claim 5 wherein said power lead is connected to theelectromechanical means, and said means responsive to the sensing meanscomprises shunting means connected to the power lead for divertingenergy from the electromechanical means until said predetermined patternof conditions is sensed. I

7. An electronic lock having an operative condition and a normallynonoperative condition and adapted to be placed in its operativecondition by operation of a plurality of selectable operators means in apredetermined sequence, comprising in combination a number ofmultivibrator stages each connected to a different selectable operatorsmeans for operation to a first condition upon subsequent operation,means interconnecting said stages for operation in accordance withbinary sequencing, sensing means collectively responsive to the onoffmeans to sense a predetermined pattern of conditions therefromconforming to a binary code, means responsive to the sensing means whensensing said predetermined pattern to render the lock operative,switching means for supplying power to operate the lock, and reset meansinterconnecting.

the respective operators means with the switching means to interrupt thepower whenever an operators means is operated out of said sequence.

8. The lock of claim 7 further comprising a source of power connected tothe switching means and to the operators means, said on-ofi meanscomprising bistable multivibrators, and said operators means comprisingswitches whereby closure of one of the switches applies a pulse to atleast one of: the switching means and at least one of themultivibrators.

9. The lock of claim 8 wherein the sensing means comprises a logicalcircuit responsive to only one set of conditions of operation of thebistable multivibrators to actuate the means responsive thereto, andmeans for selecting said one set of conditions as the predeterminedpattern from a plurality of patterns available from operation of thebistable multivibrators.

10. An electronic permutation lock comprising binary counting means,switching means for connecting a source of power to the binary countingmeans, a plurality of operators switches, circuits interconnecting theoperators switches with individual stages of the binary counting meansto cause the latter sequentially to count when the operators switchesare operated in a predetermined sequence, output circuits from thebinary counting means, sensing means comprising a logic circuitresponsive to a predetermined pattern of outputs selected from a binarycode from the output circuits, load actuating means operated by thesensing means when the logic circuit senses the predetermined pattern,and reset circuits connected between the operators switches and theswitching means to disconnect the source of power whenever an operatorsswitch is operated out of said predetermined sequence.

11. The lock of claim 10 wherein the binary counting means comprise aplurality of bistable multivibrators.

12. The lock of claim 11 wherein the switching means comprises amultivibrator and a series gate, said gate being connected between thepower source and the bistable multivibrators, and said multivibratorbeing connected to open and close the gate.

13. The lock of claim 12 wherein the load actuating means compriseelectromechanical operating means connected across the power source, andshunting means for normally diverting energy from the operating means,said logic circuit opening the shunting means when the predeterminedpattern is sensed.

14. The lock of claim 10 further comprising an alarm circuit includingan alarm connected for actuation from the reset circuits, the alarmcircuit comprising storage means responsive to each error occasioned byoperating the operators switches out of the predetermined sequence, andmeans for selecting a number of errors at the storage means to operatethe alarm.

means, and rectifiers connecting the battery means across the powersource to receive trickle charge during normal operation and to serve asemergency power when the power source fails. 1 v

1. An electronic combination lock, for operating an electromechanicalmeans, when in its operative condition and having a normallynonoperative condition, comprising in combination a plurality ofselectable operators digit switches which when operated in apredetermined sequence will switch the lock to its operative condition;a number of bistable means each connected to a different one of theselectable operators switches for operation to one condition uponoperation of the associated operators switches in said sequence and tothe other condition upon subsequent operation; means interconnectingsaid bistable means for operation in accordance with binary sequencing;output circuits for each bistable means to provide outputs indicative ofthe condition of operation; multiple switching means connected to theoutput circuits of the plurality of bistable means for preselecting thenumber of operators switches to be operated in the sequence to rendersaid lock operative; sensing means connected to the multiple switchingmeans and responsive thereto to sense a predetermined pattern ofconditions in accordance with binary code therefrom indicative of thelast digit of said sequence; means responsive to the sensing means whensensing said predetermined pattern to render the lock operative foroperating the electromechanical means; switching means for supplyingpower to operate the lock, said switching means comprising two positionoperating means for supplying power in one of its conditions ofoperation; and reset means interconnecting the operators switches to thetwo position means to interrupt the power when one of the operatorsswitches is operated out of said sequence.
 2. The lock of claim 1wherein the bistable means and the switching means comprisemultivibrators.
 3. The lock of claim 1 wherein the switching meanscomprises a monostable multivibrator including timing means forresetting it, and the reset means are connected to reset themultivibrator independently of the timing means.
 4. The lock of claim 1further comprising circuit connections from the switching means to eachbistable means to establish a predetermined set of operating conditionsamong the bistable means upon operation of the switching means to itsone condition of operation, and said switching means being operated tosaid one condition of operation by actuation of its associated operatorsswitch.
 5. The lock of claim 4 wherein said switching means comprises apower lead connected from a source of power to the bistable means, aseries gate connected in the lead to open and close it, said switchingmeans further comprising a multivibrator for closing the series gatewhen in said one condition of operation.
 6. The lock of claim 5 whereinsaid power lead is connected to the electromechanical means, and saidmeans responsive to the sensing means comprises shunting means connectedto the power lead for diverting energy from the electromechanical meansuntil said predetermined pattern of conditions is sensed.
 7. Anelectronic lock having an operative condition and a normallynonoperative condition and adapted to be placed in its operativecondition by operation of a plurality of selectable operators means in apredetermined sequence, comprising in combination a number ofmultivibrator stages each connected to a different selectable operatorsmeans for operation to a first condition upon subsequent operation,means interconnecting Said stages for operation in accordance withbinary sequencing, sensing means collectively responsive to the on-offmeans to sense a predetermined pattern of conditions therefromconforming to a binary code, means responsive to the sensing means whensensing said predetermined pattern to render the lock operative,switching means for supplying power to operate the lock, and reset meansinterconnecting the respective operators means with the switching meansto interrupt the power whenever an operators means is operated out ofsaid sequence.
 8. The lock of claim 7 further comprising a source ofpower connected to the switching means and to the operators means, saidon-off means comprising bistable multivibrators, and said operatorsmeans comprising switches whereby closure of one of the switches appliesa pulse to at least one of: the switching means and at least one of themultivibrators.
 9. The lock of claim 8 wherein the sensing meanscomprises a logical circuit responsive to only one set of conditions ofoperation of the bistable multivibrators to actuate the means responsivethereto, and means for selecting said one set of conditions as thepredetermined pattern from a plurality of patterns available fromoperation of the bistable multivibrators.
 10. An electronic permutationlock comprising binary counting means, switching means for connecting asource of power to the binary counting means, a plurality of operatorsswitches, circuits interconnecting the operators switches withindividual stages of the binary counting means to cause the lattersequentially to count when the operators switches are operated in apredetermined sequence, output circuits from the binary counting means,sensing means comprising a logic circuit responsive to a predeterminedpattern of outputs selected from a binary code from the output circuits,load actuating means operated by the sensing means when the logiccircuit senses the predetermined pattern, and reset circuits connectedbetween the operators switches and the switching means to disconnect thesource of power whenever an operators switch is operated out of saidpredetermined sequence.
 11. The lock of claim 10 wherein the binarycounting means comprise a plurality of bistable multivibrators.
 12. Thelock of claim 11 wherein the switching means comprises a multivibratorand a series gate, said gate being connected between the power sourceand the bistable multivibrators, and said multivibrator being connectedto open and close the gate.
 13. The lock of claim 12 wherein the loadactuating means comprise electromechanical operating means connectedacross the power source, and shunting means for normally divertingenergy from the operating means, said logic circuit opening the shuntingmeans when the predetermined pattern is sensed.
 14. The lock of claim 10further comprising an alarm circuit including an alarm connected foractuation from the reset circuits, the alarm circuit comprising storagemeans responsive to each error occasioned by operating the operatorsswitches out of the predetermined sequence, and means for selecting anumber of errors at the storage means to operate the alarm.
 15. The lockof claim 10 wherein the sensing means comprises multiple switching meansconnecting the output circuits to the logic circuit, and means at themultiple switching means for selecting the number of digits in thepermutation to determine the predetermined pattern.
 16. The lock ofclaim 15 further comprising battery storage means, and rectifiersconnecting the battery means across the power source to receive tricklecharge during normal operation and to serve as emergency power when thepower source fails.